Mine started at 64. I was in good shape and have no idea why it was happening. I had them occasionally in both legs at a time. 13 years later, I finally had the pain management doctor tell me to start drinking some kind of electrolyte. I started two years drinking Propel. At the time I had increased water, ate bananas and other things. Since then I am about 97% clear of them. It works. Some of those cramps were the worst pain I've ever had. By the way I did change statins but only recently. I give most credit to the Propel.